This invention relates to a projectile release mechanism for facilitating launching a jet-propelled projectile, and particulary a spherical spin-stabilized missile.
It has become increasingly important to eliminate the features associated with a ballistic trajectory ordinarily followed by rockets and other jet-propelled projectiles, by forming the projectiles as spherical spin-stabilized missiles. The spherical missile spins about an axis upwardly inclined relative to the intended straight line path of flight and aligned with the thrust axis of the propulsion jet of the missile. The missile is released following ignition or activation of the jet propellant within the missile. The propulsion is effected by the reaction of the exhaust jet of, for example, a rocket motor housed within the spherical missile shell.
Often such spherical spin-stabilized missiles are provided in conjunction with attachments secured to the front end of an assault weapon such as a rifle.
Such spin-stabilized spherical jet-propelled missiles experience difficulties in remaining stabilized during attainment of desired rotational speed and in coordinating the spinning and release of the missile. Release of the missile prior to attainment of adequate rotational speed can result in unstable flight. Delay of release after attainment of adequate rotational speed can result in a loss of propulsive range.
Consequently, attempts have been made to provide means for temporarily restraining and automatically releasing a spin-stabilized jet-propelled spherical missile during spinup. For instance, in U.S. Pat. No. 3,245,350 to J. A. Kelly, dated Apr. 12, 1966, a mechanical release is provided between a rifle barrel and a spin-stabilized spherical missile in order to selectively release the missile. However, precise automatic release is not afforded. More specifically, U.S. Pat. No. 3,554,078 to Joseph S. Horvath, dated Jan. 12, 1971, provides a fusible link for temporarily restraining and automatically releasing a spherical spin-stabilized missile during spinup. Release of the spherical rocket missile from its rotary supporting means is effected by causing hot missile rocket exhaust gas to weaken by heating or to heat and soften or melt a separate fusible link member which, prior to weakening by softening or melting, secures the missile to the rotary support means. In this patent, the separate fusible link member is of the nature of a brazing alloy serving as one part of a nozzle assembly to secure the rocket to the rotary support means. The fusible link member actually is brazed between two additional nozzle members which secure the missile to the support means. Such assembly and brazing operations not only are time consuming during manufacture but can be inaccurate and can result in increased costs as well.
The present invention is directed to providing a new and improved nozzle assembly which includes a unitary nozzle member having fusible joint means formed integrally therewith, between the missile and the rotary support means, thereby eliminating the aforsaid assembly and brazing operations and thereby considerably reducing manufacturing costs and improving accuracy.
Another problem experienced in spin-stabilized spherical jet-propelled missiles of the character described, is in the supporting and orienting means of the missile for accurate alignment about a spin axis as rotational speed is attained. The present invention provides a new and improved means between the missile exhaust nozzle and the rotary support means to insure proper alignment of the missile with its launching spin axis during initial separation of the integral fusible joint means.